Localized frequency comb and formation of embedded solitons in silicon-based slot waveguides

摘要

We explore the possibility to excite the so-called embedded solitons inspecially designed slot waveguides based on silicon and silica or siliconnanocrystals. This requires the excitation of the structure with quasi-TMpolarized pulses -- for which Raman effect is absent -- and at a specificinfrared wavelength for which only the second- and fourth-order group velocitycoefficients are non-vanishing. Pulses launched in these conditions willgenerate a spectrally localized continuum, associated to a frequency combcoming from the spectral interference of many embedded solitons.